In addition to the visualization, already previously carried out, of coronary heart diseases, modern techniques of computed tomography, in particular multi-slice computed tomography, also enable a visualisation of the heart for a functional analysis. Here, the recording of the 3D image data of the heart is performed after a contrast agent injection, in order to be able to distinguish regions supplied with blood and therefore enriched with contrast agent, clearly from structures not supplied with blood.
An essential precondition for the functional cardio analysis with the aid of 3D image data of a tomographic modality is a suitable visualization of the image data, in which the viewer can at any time detect and/or interrogate the precise position of an arbitrary point in the heart that he has marked in the image. Above all, this requires a correct delimitation between the left ventricle, the right ventricle and the myocardium.
Such a delimitation requires a segmentation of the 3D image data into the individual regions of the heart. Recently, use has increasingly been made for this purpose of model based methods, for example those based on the so called “Active Shape Model” (ASM) or the so-called “Point Distribution Model” (PDM). Details on these models, which are built on the basis of training data and adapted to the existing 3D image data, are to be found, for example, in T. Cootes et al., “Statistical Models of Appearance for Computer Vision”, University of Manchester, Dec. 5, 2000, the entire contents of which is hereby incorporated herein by reference.
However, a segmentation of the left ventricle and of structures of the myocardium in 3D image data of the heart has so far been possible with the aid of such a model only through time consuming manual interaction with the user. Assigning the individual regions of the heart in accordance with a segment model such as the 17 segment model of the American Heart Association (AHA segment model) has also so far required manual interaction with the user. During this manual interaction, the user has had to mark in the images displayed boundary points of the septum on the basis of which it has been possible to assign the segment model in conjunction with the already segmented image data. Such a segment model divides the heart into basal, mid-ventricular and apically defined regions to which reference is respectively made by specialists when describing the heart.